Your computer's command-line is one of the most powerful tools in your development toolset. If you've never used a command-line or if you're still wondering what it even is, don't worry. We are going to take a look at some common commands and patterns that you will use to complete the rest of the book and set you up for future command-line usage.

First, we need to discuss the differences between operating systems and their command-line interfaces that we will use. We are going to specifically cover two topics: Terminal on Mac/Linux and PowerShell on Windows.

Mac OS X Terminal: If you're using a Mac (or Linux), Terminal comes preinstalled as a system application. Simply search for it and run the application, and you're all set.

Windows PowerShell: Our Windows setup is a bit different in that we will use an additional application as our command-line interface. Windows PowerShell is a powerful application that will make your command-line experience much...